The present invention relates to a liquid jetting apparatus for jetting a liquid, such as ink, glue or manicure, an image recording apparatus incorporating the liquid jetting apparatus and a method of driving the liquid jetting apparatus.
A related technique will now be described such that an ink jet recording head and an ink jet recording apparatus incorporating the recording head are described.
To perform both color recording and monochrome recording, an ink jet recording head structured to be capable of discharging ink in different colors, such as black ink, cyan ink, magenta ink and yellow ink and an ink jet recording apparatus having the recording head mounted thereon have been suggested. A portion of the recording apparatuses is arranged to use high permeable ink, such as dye-type ink, exhibiting excellent permeability into recording paper in order to prevent mixture of ink and improve the quality of a color image.
The foregoing structure, however, suffers from a problem in that the quality of a monochrome image, such as a document, deteriorates in spite of capability of improving the quality of a color image. That is, high permeable ink has an advantage that occurrence of color mixture can be prevented because high permeable ink quickly permeates into recording paper. High permeable ink encounters a problem of spreading in the radial direction of the dot. Therefore, the color of the edge portion of the recorded dot gradually fades toward the outside. When characters or the like are recorded, the boundary portion is blurred.
To record dots each having a sharp edge, it is preferable that low permeable ink is used which has a low degree of permeation into recording paper as compared with high permeable ink. When a plurality of recording heads are mounted to correspond to the types of ink, the apparatus becomes too complicated and the size is enlarged excessively.
Since the characteristics of the recording heads must be made coincide with one another, a complicated adjustment operation must be performed. Therefore, development of a small-size recording head which is capable of discharging plural types of ink having different physical properties, including the permeation, has been required.
In view of the foregoing, an object of the present invention is to provide a liquid jetting apparatus which is capable of discharging plural types of liquids having different physical properties and which permits size reduction, an image recording apparatus incorporating the liquid jetting apparatus, a method of operating the liquid jetting apparatus, and a computer-readable recording medium storing the method.
In order to achieve the above object, according to the first aspect of the invention, there is provided a liquid jetting apparatus comprising:
a first group of nozzles for respectively ejecting a first kind of liquid droplet;
a second group of nozzles for respectively ejecting the first kind of liquid droplet; and
a third group of nozzles for respectively ejecting a second kind of liquid droplet having different physical property from the first kind of liquid,
wherein the amount of liquid droplet ejected from the nozzle in the first group and the amount of liquid droplet ejected from the nozzle in the second group are different from each other.
Note that the xe2x80x9cphysical propertiesxe2x80x9d of the liquid means characteristics including permeation, viscosity, density, surface tension or the like.
According to the second aspect of the invention, the amount of liquid droplet ejected from the nozzle in the second group and the amount of liquid droplet ejected from the nozzle in the third group are identical with each other.
According to the third aspect of the invention, the nozzles in the first group include a plurality of nozzle arrays.
According to the fourth aspect of the invention, the nozzles in the second group and the third group respectively include at least one nozzle array. The nozzle array in the second group and the nozzle array in the third group are arranged adjacent to one another.
According to the fifth aspect of the invention, there is also provided a liquid jetting apparatus comprising:
a plurality of nozzle arrays; and
a plurality of divided nozzle arrays defined by dividing at least one of the nozzle arrays into a plurality of nozzle blocks,
wherein liquids ejected from the respective divided nozzle arrays have different physical properties from each other.
According to the sixth aspect of the invention, the divided nozzle arrays are defined with respect to at least two of the nozzle arrays.
According to the seventh aspect of the invention, the nozzles in one nozzle array including the divided nozzle arrays are arranged so as to form a zigzag configuration with respect to the nozzles in another nozzle array including the divided nozzle arrays.
According to the eighth aspect of the invention, both ends of the respective nozzle arrays are dummy nozzles which are not subjected to the liquid ejection.
According to the ninth aspect of the invention, the liquid jetting apparatus further comprises:
pressure chambers for generating pressure to eject the liquid from the associated nozzles; and
a dummy pressure chamber which is not subjected to the liquid ejection is provided between the nozzles in the respective adjacent divided nozzle arrays.
According to the tenth aspect of the invention, at least one of the nozzle arrays is not divided into the divided nozzle arrays.
According to the eleventh aspect of the invention, at least two of the nozzle arrays are not divided into the divided nozzle arrays. The nozzles in one nozzle array not including the divided nozzle arrays are arranged so as to form a zigzag configuration with respect to the nozzles in another nozzle array not including the divided nozzle arrays.
According to the twelfth aspect of the invention, there is also provided an image recording apparatus for recording an ink image on a recording medium, comprising the liquid jetting apparatus of the first to fourth aspects. Here, the first kind of liquid is a first kind of ink and the second kind of liquid is a second kind of ink.
According to the thirteenth aspect of the invention, the second kind of ink has a higher permeability with respect to the recording medium than the first kind of ink.
According to the fourteenth aspect of the invention, there is also provided an image recording apparatus for recording an ink image on a recording medium, comprising the liquid jetting apparatus of the fifth to eleventh aspects. Here, the divided nozzle arrays are composed of a first divided nozzle block for ejecting a yellow ink droplet, a second divided nozzle block for ejecting a magenta ink droplet and a third nozzle block for ejecting a cyan ink droplet.
According to the fifteenth aspect of the invention, the second nozzle block is arranged between the first nozzle block and the third nozzle block.
According to the sixteenth aspect of the invention, there is also provided an image recording apparatus for recording an ink image on a recording medium, comprising the liquid jetting apparatus of the sixth to eleventh aspects. Here, the liquid ejected from a divided nozzle array in one nozzle array is a first kind of ink, and the liquid ejected from a divided nozzle array in another nozzle array adjacent to the divided nozzle array for ejecting the first kind of ink is a second kind of ink. The first kind of ink and the second kind of ink are homochromatic. The first kind of ink has a higher color density than the second kind of ink.
According to the seventeenth aspect of the invention, there is also provided an image recording apparatus recording an ink image on a recording medium, comprising the liquid jetting apparatus of the fifth and ninth aspects. Here, a first kind of ink and a second kind of ink having a higher permeability with respect to the recording medium than the first kind of ink are allocated as the liquid ejected from the respective nozzle blocks.
According to the eighteenth aspect of the invention, there is also provided an ink image on a recording medium, comprising the liquid jetting apparatus of the tenth or eleventh aspect. Here, the respective divided nozzle array eject either one of a first kind of ink or a second kind of ink having a higher permeability with respect to the recording medium than the first kind of ink. The respective nozzle arrays not including the divided nozzle array eject another one of the first kind of ink and the second kind of ink.
According to the ninth aspect of the invention, at least one of the nozzle arrays not including the divided nozzle arrays ejects a black ink droplet.
According to the twelfth aspect of the invention, at least one nozzle array is arranged between the nozzle array for ejecting the black ink droplet and a nozzle array including a divided nozzle arrays for ejecting an yellow ink droplet.
According to the twenty-first aspect of the invention, the first kind of ink includes a pigment-family ink and the second kind of ink includes a dye-family ink.
According to the twenty-second aspect of the invention, the pigment-family ink is a black ink and the dye-family ink is a colored ink.
According to the twenty-third aspect of the invention, the image recording apparatus further comprises a capping member for sealing a surface on which the nozzles are formed. The capping member is partitioned in accordance with the kind of ink ejected from the nozzles to be sealed.
According to the twenty-fourth aspect of the invention, there is also provided a method of driving a liquid jetting apparatus having nozzles, comprising the steps of:
defining a first group of nozzles for respectively ejecting a first kind of liquid droplet;
defining a second group of nozzles for respectively ejecting the first kind of liquid droplet;
defining a third group of nozzles for respectively ejecting a second kind of liquid droplet having different physical property from the first kind of liquid; and
setting the amount of liquid droplet ejected from the nozzle in the first group so as to be different from the amount of liquid droplet ejected from the nozzle in the second group are different from each other.
According to the twenty-fifth aspect of the invention, the driving method further comprises the step of setting permeabilities with respect to an object to which the liquid is jetted of the first kind of liquid and the second kind of liquid so as to be different from each other.
According to the twenty-sixth aspect of the invention, the amount of liquid droplet ejected from the nozzle in the first group is greater than the amount of liquid droplet ejected from the nozzle in the second group.
According to the twenty-seventh aspect of the invention, the first nozzle group and the second nozzle group are used when only the first kind of liquid is ejected. The second nozzle group and the third nozzle group are used when both of the first kind of liquid and the second kind of liquid are ejected.
Accordingly, since the quantity of first liquid can be determined to meet the purpose of the recording operation, a single liquid jetting apparatus can be adapted to a variety of purposes. Thus, a necessity of providing the liquid jetting apparatuses for the purposes can be eliminated. Therefore, the structure can be simplified and the size reduction is permitted.
According to the twenty-eighth aspect of the invention, the third nozzle group includes a plurality of nozzle arrays. The second kind of liquid includes a plurality kinds of liquids having physical properties are different with each other, which are allocated with respect to the respective nozzle arrays.
Accordingly, plural types of liquids having different physical properties can be ejected from different nozzle blocks. Since the nozzle array is divided into a plurality of nozzle blocks, one nozzle array is able to discharge plural types of liquids. As a result, even a single liquid jetting apparatus can be adapted to a variety of purposes. As a result, the necessity of providing liquid jetting apparatuses for individual purposes can be eliminated.
According to the twenty-ninth aspect of the invention, there is provided a computer-readable recording medium for recording a program to cause a computer to function as:
a first ejection controller for controlling a liquid jetting apparatus comprising a first group of nozzles and a second group of nozzles for jetting a first kind of liquid droplet and a third group of nozzles for jetting a second kind of liquid droplet having a different physical property from the first kind of liquid such that the amount of liquid droplet ejected from the nozzle in the first group and the amount of liquid droplet ejected from the nozzle in the second group are different from each other.
According to the thirtieth aspect of the invention, the amount of liquid droplet ejected from the nozzle in the first group is greater than the amount of liquid droplet ejected from the nozzle in the second group.
According to the thirty-first aspect of the invention, the recording medium causes the computer to further function as:
a second ejection controller for controlling the liquid jetting apparatus such that the nozzles in the first and second groups are used when only the first kind of liquid is ejected; and the nozzles in the second and third groups are used when the first and second kinds of liquids are ejected.
Here, the computer is caused to function as at least one of the first ejection controller and the second ejection controller.
According to the thirty-second aspect of the invention, there is provided a computer-readable recording medium for recording a control program to cause a computer to function as:
a liquid-kind recognizer for recognizing respective ink kinds ejected from the nozzles in the first, second and third groups of the liquid jetting apparatus of the first to fourth aspects of the invention;
a drive waveform selector for selecting a waveform of a drive signal for driving the liquid jetting apparatus to eject the liquid droplet, which is optimum with respect to each ink kind recognized by the liquid-kind recognizer; and
a ejection controller for ejecting the liquid droplet using the drive signal selected by the drive waveform selector.
According to the thirty-third aspect of the invention, there is provided a computer-readable recording medium for recording a control program to cause a computer to function as:
a liquid-kind recognizer for recognizing respective ink kinds ejected from the nozzles in each nozzle block of the liquid jetting apparatus of the fifth to eleventh aspects of the invention;
a drive waveform selector for selecting a waveform of a drive signal for driving the liquid jetting apparatus to eject the liquid droplet, which is optimum with respect to each ink kind recognized by the liquid-kind recognizer; and
a ejection controller for ejecting the liquid droplet using the drive signal selected by the drive waveform selector.